Elevator for lifting persons or loads



March 8, 1960 KRlsTEK ETAL 2,927,661

ELEVATOR FOR 1.1mm; PERSONS OR' LOADS Filed Nov. 30, 1955 2 Sheets-Sheet1 %g ga I j 5 WI D t INVENTORS. f'mamzeflfi lstek BY Eager: Rafa/2e?March 8, 1960 E. KRISTEK ETA!- 2, 27,661

ELEVATOR FOR LIFTING PERSONS OR LOADS Filed Nov. 30, 1955 2 Sheets-Sheet2 Mel 2,927,661 ELEVATOR FUR LIFTING PERSONS R LOADS Emanuel Kristek andEugen Reichel, G'ottw'aldov, Czechoslovakia, assignors to Zavody piesnhostrojirenstvi Gtlanttwaldov, narodni podnik, G'ottwaldov, Czechoslova aApplication November '30, 1955, Serial No. 550,130

Claims priority, application Czechoslovakia December 15, 1954 Claims.(Cl. 187-17) The present invention relates generally to improvements inelevators, and more particularly is directed to an elevator with a cageadapted to travel vertically or along an inclined path for liftingpersons or heavy loads.

Most known elevators comprise a cage suspended by a cable from ahoisting mechanism or winch, and such elevators are of intricateconstruction owing to the indispensable requirements of safety, apartfrom having numerous other disadvantages. The cable has to be frequentlychecked and replaced and at higher velocities, dithculties areencountered by reason of the flow of air around the moving cage, so thatthe cross-sectiona1 area of the shaft has to be considerably greaterthan that of the cage. Furthermore, the arrangement of the hoisting orwinch mechanism above the shaft increases the overall height of thebuilding and disturbs its appearance, while the elevator cannot travelto the very top of the building.

The main object of the present invention is to provide an elevator thatis free of the above disadvantages and has a number of characteristicadvantages which will ap pear from the following description ofillustrative embodiments.

In accordance with an aspect of this invention, an elevator comprises acage movable in sealing engagement in an elevator shaft, with the cagebeing lifted or retained in its position by a difference between the airpressures in the shaft below and above, respectively, the cage. 7

The invention will be more clearly understood from the followingdescription of illustrative embodiments thereof which is to be read inconnection with the accompanying drawings, wherein:

Fig. 1 is a vertical sectional view of an elevator embodying theinvention;

Fig. 2 is a horizontal sectional view of the cage included in theelevator of Fig. 1, and with a locking device provided in the cage beingshown in an engaged position thereof;

Fig. 3 is a view similar to that of Fig. 2, but with the locking deviceshown in its released position;

Fig. 4 is a detail side elevational view of means provided in theelevator embodying the present invention for the purpose of connectingelectrical equipment carried by the elevator cage with a source ofelectricity along the elevator shaft;

Fig. 5 is a diagrammatic side elevational view of another embodiment ofthe present invention; and

Fig. 6 is a diagrammatic view of an electro-hydraulic adjusting unit forcontrolling the movement of a valve included in each of the embodimentsof the invention illustrated by Figs. 1 and 5, respectively.

Referring to Fig. 1 in detail, it will be seen that an elevatorembodying the invention includes a cage 2 arranged for movement in ashaft 1 and having a floor 3 and ceiling 4 which are provided withsealing members 5 and 6 which extend into resilient engagement with thesurface of shaft 1 for closing the space between the cage 2 and theshaft 1. A fan or blower 8 driven by a motor 10 is mounted adjacent theshaft in a chamber 7, and the discharge of the fan delivers air underpressure through a conduit 11 to the lower portion of shaft 1. Theconduit 11 opens into the shaft at a distance a above its bottom. A pipe12, adapted to be closed by a valve 14, branches off from the conduit 11and opensinto the shaft 1 at the bottom of the latter, and a tube 15also branches off from the conduit :11 and opens into a storage space orpressure accumulator 16.

The conduit 11 is provided with a non-return or check valve 17permitting flow only in the direction toward the shaft 1, and conduit 11is also provided with a control valve 18 operated by a unit 20 which,for example, may include an electric motor driving an hydraulic pumpwhich supplies fluid to a cylinder having a piston slidable therein andconnected to the valve 18, all in a known manner. The bottom of theshaft 1 is equipped with a spring buffer 21 preventing the cage 2 fromabutting against the bottom of the shaft. At a distance b from the topof the shaft 1, a pipe 22 extends from the shaft to the chamber 7, whereit is attached to the suction side or inlet of the fan 8. The pipe orconduit 22 is provided with a non-return or check valve 23 permittingflow therethrough only in the direction away from shaft 1, and anon-return or check valve 24- is mounted in a pipe 25 opening fromconduit 22 to the atmosphere to admit atmospheric air in case a vacuumis formed in the conduit 22. The valves 17 and 23 are arranged in themanner described so as to allow the passage of air through the shaft 1only in the upward direction.

The cage 2 (Fig. 2) is guided in the shaft 1 by means of rollers 30which are rotatably carried by the cage and in rolling contact with theinterior of the shaft. Cage 2 also is formed with a channel 31 (Fig. 1)passing vertically therethrough and adapted to be closed by a valve 32which is controlled, for instance, by a unit 33 similar to the unit 20previously mentioned herein. A suitable arrangement for the unit 33 isshown in Fig. 6 to include a reversible electric motor 33:: having itsshaft 33b connected to a pump 330 for hydraulic fluid which is fed bythe pump to one end or the other of a cylinder 33d having a piston 33emovable therein and connected, by a suitable mechanical linkage 33 tothe valve 32 so that, by controlling the direction of rotation of motor33a, the valve 32 may be opened and closed, as desired. The walls of theshaft are further equipped with metal rails 34 (Figs. 1, 2 and 4) whichare suitably insulated from each other. Resilient contact strips 35(Figs. 2 and 4) are mounted on the cage 2 and are adapted to move alongthe metal rails 34, to provide connections between electric equipmentcarried by the movable cage and other fixed electric equipment of theelevator. In order to exactly position the elevator cage at theindividual floors, a known arrangement is employed that includeselectromagnets 36 embedded in the well of shaft 1 and eifective, whenenergized, to actuate a magnetic relay 37 on the cage 2 of the elevatoras such relay comes adjacent the energized electromagnet.

The cage is secured at the various floors by means of pawls 38 movablycarried by the cage and adapted to be laterally projected from thelatter to engage in apertures 39 in the wall of the shaft 1. The pawls38 may be laterally projected (Fig. 2) and retracted (Fig. 3) by meansof a unit 46) which may be similar to the unit 33 previously describedwith reference to Fig. 6, and which is connected to a link 40a which is,in turn, pivotally connected to a radial arm 40b extending from acentrally pivoted bell-crank 400. The opposite ends of bell-crank 400are connected, by pivoted links or rods 49a, to the pawls 38 so that thelatter are projected and retracted in response to rocking of bell-crank460. The presently described embodiment of the invention is completed byan air-tight door 4-1 (Fig. l) for closing the usual opening in theshaft 1 at each lioor.

It may be proved by a simple calculation that, in order to cause thecage to float in the shaft, an air pressure capable of raising 300 to400 mm. of water in a column has to act against the bottom of the cage.Such a pressure may be supplied by a two-stage, medium pressure fan witha relatively good efficiency, which is equal to the efficiency ofexisting elevator machines, particularly when the latter are equippedwith worm gearings.

When the fan 8 delivers air to the conduit 11 and the valve 18 is moreor less open, the pressure of air acts on the bottom of the cage 2, and,if the valve 32 is closed, the cage moves upwards. The air from theshaft above the elevator opens the check valve 23 and flows through theconduit 22 to the fan 8 in chamber 7. By this circulation of air thekinetic energy thereof is utilized and the consumption of new,unpurified air from the outside is reduced.

The cage is stopped at a selected fioor by the cooperation of therelated electromagnets 36 with the magnetic relay 37 to close suitablecircuits connected to units 20 and 40 by which the valve 18 is closedand the pawls 38 are pushed into the corresponding apertures 39 at theselected floor. When it is desired to again move the elevator cage, thevalve 18 is opened and the pawls 38 are retracted or withdrawn.

During downward movement of the cage 2, the valve 18 is closed and thevelocity of downward movement is controlled by the valve 32 past whichair flows through the channel 31 from the space below the cage to thespace above the cage.

The spaces a and b of the shaft 1 serve as air cushions at the oppositeends of the shaft and soften the impact of the cage at the limit of itsupward movement or when the cage falls in the event of a failure of apart of the device.

The non-return or check valves 17 and 23 prevent the cage 2 from fallingto the bottom of the shaft in case of stoppage of the fan or a suddenleak in the shaft caused, for instance, by the bursting of any of thedoors 41 below the cage 2. The buffer 21 softens the impact of the cage2 against the bottom of shaft 1 when the sealing members and 6 aredamaged and prevents contact of the cage with the bottom surface of theshaft 1. If for any reason, the cage is displaced in the portion a ofthe shaft, it may be lifted by opening the valve 14 to admit air at anelevated pressure below the cage. During normal operation of theelevator, the valve 14 must be closed in order to insure the operationof the lower end portion a of the shaft as an air cushion. The storagespace or accumulator 16 supplies air to shaft 1 below cage 2 if the rateof increase of the volume below the cage, during upward movement of thelatter, momentarily exceeds the rate of delivery of air by fan 8.

It is one of the advantages of the elevator according to the inventionthat a plurality of elevators disposed at not too great a distance fromeach other may be operated by one motor and fan outside the building inwhich the elevator is mounted, and thus it is easy to achieve sound 4insulation and to prevent vibrations from being transmitted to thebuilding.

In the embodiment of the invention described with reference to Figs. 1-4and 6, the channel 31 is opened in order to permit the cage to movedownwards, and then connects the space below the cage with the spaceabove the cage in the shaft. Under certain circumstances it may bepreferable to effect such connection by means of a tube 310 providedoutside the shaft, as shown in Fig. 5, and extending between theconduits 11a and 22a corresponding to the conduits 11 and 22 of thearrangement of Fig. l. The external tube 31a has a valve 32a thereincorresponding to the valve 52 and similarly actuated by anelectro-hydraulic device 33 so that, when valve 32a is opened, air canflow from the space in the shaft below cage 2 through tube 31a to thespace above the cage, as indicated by the arrows in broken lines.

Although illustrative embodiments of the invention have been describedin detail herein with reference to the accompanying drawings, it is tobe understood that the invention is not limited to those preciseembodiments, and that various changes and modifications may be effectedtherein by one skilled in the art without departing from the scope orspirit of the invention, except as defined in the appended claims.

We claim:

1. An elevator for lifting persons or loads comprising an airtightelevator shaft, an elevator cage mounted for movement in said shaft,means for effecting airtight sealing of said cage in said shaft, fanmeans having a relatively low air pressure inlet and a relatively highair pressure discharge, first conduit means extending from saiddischarge and opening into said shaft adjacent the lower end of thelatter, second conduit means opening from said shaft adjacent the upperend of the latter and extending to said inlet of the fan means so thatthe latter is operative to produce relatively high and low pressures insaid shaft below and above, respectively, said cage for supporting, andcausing upward movement of the latter in said shaft, adjustable valvemeans in said first conduit means for controlling the flow of airtherethrough, a check Valve in said first conduit means permitting flowthrough the latter only in the direction from said discharge of the fanmeans to said shaft in order to prevent uncontrolled dropping of saidcage in the event of a failure of said fan means, means defining achannel connecting the space in said shaft below said cage with thespace in said shaft above the cage, and an adjustable valve interposedin said channel to close the latter during upward movement of the cageand to control the fiow of air through said channel from said spacebelow the cage to said space above the cage during the controlleddownward movement of said cage by gravity.

2. An elevator as in claim 1; wherein said first and second conduitmeans communicate with said shaft at locations spaced from said lowerand upper ends, respectively, thereby to provide air cushions at theopposite ends of the shaft for preventing violent contact of said cagetherewith.

3. An elevator as in claim 1; wherein said second conduit means has anaperture opening to the atmosphere and valve means in said apertureopening to permit the entry of atmospheric air when the pressure in saidsecond conduit means falls below atmospheric pressure, said secondconduit means further having a check valve therein interposed betweensaid aperture and said shaft and permitting flow through said secondconduit means only in the direction from said shaft to said inlet of thefan means.

4. An elevator as in claim 1; further comprising movable pawls carriedby said cage and adapted to be laterally projected from the latter, saidshaft having apertures in the walls thereof at predetermined locationsand adapted to receive said pawls for releasably retaining said cage atsaid predetermined locations.

5. An elevator as in claim 1; wherein said first and second conduitmeans communicate with said shaft at locations spaced from said lowerand upper ends, respectively, thereby to provide air cushions at theopposite ends of the shaft for preventing violent contact of 7 cagedescends to a' level below the point where said first conduit meanscommunicates with said shaft.

References Cited in the file of this patent UNITED STATES PATENTS 'MabbsJan. 11, 1887 Fordyce Oct. 27, 1896 Warren Oct. 8; 1901 Davy Apr; 13;1920 Goddard June 20, 1950

